Release v0.21.0

Release Notes

This release introduces automatic slash command syncing from MCP prompts, a new interactive prompt designer, and renames the LSP binary for clarity.

hexai-lsp renamed to hexai-lsp-server — Update your editor configuration (e.g., Helix language-server.hexai.command) and any scripts referencing the old binary name. The log file also moves to hexai-lsp-server.log.

Slash command sync — MCP prompts now automatically export as Markdown files (hexai-{name}.md) to a configurable directory, keeping your slash commands in sync with prompt changes. Enable with slashcommand_sync = true in [mcp] config or --slashcommand-sync flag.
Backfill existing prompts — Run hexai-mcp-server --sync-all to export all existing prompts to slash command files in one shot.
design_prompt meta-prompt — A new built-in interactive prompt that guides you through creating a brand new prompt template from scratch with minimal questions: purpose, arguments, metadata, preview, and save.

Atomic file writes — Slash command files are written via temp file + rename to prevent partial writes if interrupted.
MCP config in TOML — slashcommand_sync, slashcommand_dir, and prompts_dir are now configurable under [mcp] with corresponding HEXAI_* environment variable overrides.
Config merging — MCP settings properly propagate through per-project .hexaiconfig.toml overrides.

go install codeberg.org/snonux/hexai/cmd/hexai-lsp-server@latest
go install codeberg.org/snonux/hexai/cmd/hexai-mcp-server@latest